I have exactly he same vexing problem with my EML described by Vegasgo. I have a 2001 Vauxhall Omega 3.2 MV6 which until recently had never given me a moment’s trouble. Three months ago, the Bosch Engine Control Unit (engine management) warning light came on. Since then, three different Vauxhall dealerships have charged me a total of over £400 to test the system on their ‘Tech-2’ computer diagnostic machines and subsequently cleaned and then replaced its O2 and Lambda sensors (after diagnostic tests highlighted their fault codes). But each time, after running the car for another 100 miles or so, the warning light has re-appeared.
Now my local Vauxhall dealer, Evans Halshaw in Wolverhampton, says the only solution is to replace the ECU with a new unit costing £1,000 (parts and labour) which is a lot of money to spend on an old car. I rang Vauxhall’s customer service department who were useless and just told me to go back to my local dealer! Meanwhile, several car breakers yards have offered me salvaged ECUs from scrapped 3.2 Omegas for prices between £35 and £300, but my Vauxhall dealership says that unless any ‘used’ ECU comes with its original immobilisation and programming codes, it will not work in my car. And, to confuse the picture even further, when I sought independent advice through the Internet, several auto electronic re-programming firms offered to repair my existing ECU for prices ranging from £40 to £200 – but said I’d have to get it removed from my car and sent to them – and there would be no guarantee the ECU warning light wouldn’t still come back on!
Despite the constant presence of the ECU warning light and slightly reduced fuel economy, the car drives perfectly well and, since it’s done only 67,000 miles and is otherwise in mint condition, I don't want to get rid of it. Does ANYONE have a suggestion as to the best way forward? Surely there must be a way of getting this ECU/EML problem fixed cheaply but reliably!!?